Sand-milling apparatus.



E. B. MANLEY.

SAND MILLING APPARATUS.

APPLICATION FILED on. 22. 1914.

5 1 9 1 P0 11 O N d 6 t H G l a D1 EDWARD B. MANLEY, 0F ROCKTON, ILLINOIS, ASSIGNOR T0 ROCKTON MOULDING SAND' COMPANY, OF ROCKTON, ILLINOIS, A CORPORATION OF ILLINOIS.

SAND-MILLING APPARATUS.

icense.

Specification of Letters Patent. Patagntedl N 16 19][5 Application filed October 22, 1914. Serial No. 868,095. I

To all whom it may concern:

Be it known that I, EDWARD B. MANLEY, a citizen of the United States, residing at Rockton, in the county of Winnebago and State of Illinois, have in vented certain new and useful Improvements in Sand-Milling Apparatus, of which the following is a specification.

This invention relates to a new and improved apparatus for treating molding sand between the mine and the. foundry for the purpose of bringing it into a condition fit to be used in the molds without sifting or other preliminary treatment.

Heretofore, so far as I am aware, it has been the general practice to ship molding sand direct from the mine to the foundry in the condition in which it is obtained from the mine. This practice necessitates screening or other treatment of the sand at the foundry to bring it into a condition suitable for use in the molds. Molding sand, as is well known, contains a considerable percentage of clay and moisture; and as it comes from the mine it is in a mixed condition as regards the size of the particles, varying all the way. from comparatively fine grains to lumps of considerable size. Furthermore, this materialnot infrequently .eontains stones and other foreign matter,

thus making it necessary to eliminate the lumps, stones, and other foreign matter and bring the material to a uniform loose and free granular condition before it is fit for use in molding operations. Efforts to treat this material by mechanical means other than screening so as to bring it to a fit condition for use have been attended with considerable difficulty, owing mainly to the sticky character of the material and its great tendency to pack and clog any milling device used to effect disintegration. After a long series of experiments with various milling devices, I have at length discovered a milling apparatus which successfully handles this material, eliminating the lumps, and bringing it to a free, loose and uniform texture, which apparatus forms the subject matter of the present invention, and is hereinafter described in detail.

The apparatus of my invention is chiefly characterized by the employment of a steel cylinder or drum that is provided or. its cylindrical surface with a series of radially projecting teeth, preferably grouped in .'plate suspended from a point substantially vertically above the axis of the drum so as to gravltate toward the teeth of the latter,

but be capable of automatically swinging away from the drum to permit the passage of stones and to prevent the packing and clogging of the material between the drum and the abutment member. In the accompanying drawing I have illustrated a practical and preferred embodiment of the invention which I have found to operate satisfactorily, and referring thereto;

Figure 1 is a side elevation of my improved sand milling apparatus, with the del very chute partly broken out and in section. Fig. 2 is a vertical section on the line 22 of Fig. 1. Fig. 3 is a detail elevation of the toothed drum. partly broken out to show the tooth securing means. Fig. 4 is an end elevation, partly broken out and 1n vertical section, of the toothed drum; and Fig. 5 is a detail perspective View of one of the teeth of the drum, illustrating a format-ion which relieves the tenon or shank of the tooth from breaking strain.

In the drawing 6 designates a suitable frame structure, which supports the upper end of a conveying frame 7 on which is mounted an endless belt conveyer 8 of a' well known type, the upper end of the con veyer belt passing around a drum 9 driven from a power belt 10 through pulley 11, countershaft l2, pinion 13, and spur gear ll on the drum shaft. 1

Mounted in the frame is arectangular vertical delivery chute 15, in and across the upper end of which is suitably journaled a drum shaft 16 carrying on one enda pulley 17 driven by a belt 17. Fast on the shaft 16 and extending between opposite walls of the chute 15 is a boiler steel hollow cylinder or drum 18,'in'the cylindrical surface of which are mounted a number of radially projecting teeth 19, preferably grouped in spiral form around the surface of the drum. as cloariy shown in. Fig. Each tooth, as shown in Figs. 4. and 5, is formed at its inner end with a. threaded shank or' tenon 20 .which passes through a hole in the surfacesurface of the shell, each of said fastening bars accommodating one longltudmal row of teeth. By reference to Fig. 5 it will be seen that each tooth is, in cross-section, of a generally wedge form, its wider and slightly rounded edge 22 being the foremost edge, or that which strikes and beats the material during the rotation of the drum. The tenon 20 is set toward the wider edge of the tooth, as clearly shown in Fig. 5, So that the remaining portion 23 of the inner end of the tooth abutting against the outer surface of the drum resists the transverse breaking strain imposed on the tooth in service, thereby relieving the tenon 20 of such strain, and reducing the strain borne by the latter to substantially a lengthwise or pulling strain. To prevent the entrance of sand to the interior of the drum. which would prevent its uniform action. the ends of the latter are securely sealed bv end plates 2i attached by machine screws :25 to annular flanges 26 on the ends of the cylinder shell. The toothed drumis driven at a high rate of speed in a dlrection indicated by the arrow in Fig. 1, and'coiiperating therewith in the milling of the sand is a yieldable abutment herein shown as taking the form of a concave abutment plate 27 that is secured by bolts 28 to the lower ends of a pair of arms 29, which latter are pivotally suspended from a pivot rod 30 carried by an overhead support 31 and substantially in vertical line with the axis of the toothed drum, as clearly shown in Fig. 1. As a result of this manner of mounting the abutment plate 27, it normally gravitates toward the. teeth of the drum, but is free to swing outwardly or away from the latter to the extent permitted by the fore-and-aft width of the chute 15. to permit the passage of large stones or other unyielding foreign material, as well as to 'prevent packing of the material and consequent overheating of the drum in the passage of the material between the latter and the abutment plate.

In the operation of the apparatus the sand in the form in which it comes from the mine is delivered in substantially uniform quantities by a screw convever or otherwise on to the lower end of the inclined conveyer belt 8. and the latter is driven at such a speed as to throw the material from its upper end with sufiicient force to cause it to flow in a substantially continuous and uniform stream directly into the throat between the outer or descending side of the drum and the concave wall of the abutment plate. In preferred practice. the driun is driven at a rate of about one thousand revolutions per minute. in consequence of which the teeth effect a very thorough and uniform disintegrating and reducing action on the lumpy stock. thoroughlv breaking up and eliminating the lumps and causing the material to fall in a substantially uniform shower through the delivery chute 15. From the latter the material may be delivered by another cross conveyer into a railway car, or it may be simply piled up beneath the delivery chute to be subsequently removed and shipped. During the operation of the apparatus, the abutment plate 27 is constantly vibrating back and forth, yielding outwardly under the presence of any excess or temporary glut of the stock in the throat or ofany stone or hard lump of foreign material which tends to clog the throat. In this connection I may say that I have found by thorough test that a rigid or immovable abutment plate will not answer when handling this class of material, since in that case the throat will pack and clog up in a very short time. I have also found that if the material be delivered directly onto the top of the drum and carried down by the latter, instead of being poured directly into the throat formed between the drum and the abutment plate, the apparatus will not operate satisfactorily.

The stock as it comes from the delivery chute 15 of the apparatus is in a finely divided and uniform condition, not requiring any screening or other treatment at the foundry to fit it for use in molding operations.

From the foregoing it will be apparent that by means of my invention it is possible to furnish to foundrymen a superior quality of molding sand ready for immediate use. Such foreign material as stones and the like are readily discernible in the matter discharged from the chute l5 and may be picked out and discarded by an attendant watching the delivery of the milled product, so as to fully insure a condition of the material that shall not require any further treatment preliminary to its use in the foundry. WVhile the details of structure and arrangement shown and described herein are believed to give the most perfect results obtainable in an apparatus of this character, yet it will be obvious that these details may be varied to some extent without involving any departure from the principle or sacrificing any of the advantages thereof; hence I do not limit the invention to the exact structure and arrangement disclosed except to the extent clearly indicated in specific claims.

I claim:

1. In a sand-milling apparatus, the combination of a rotary toothed drum, depending abutment plate-suspending means pivotally hung from a point substantially vertically above the axis of said drum, and a concave abutment plate secured to the lower end of said suspending means and cooperating with said drum. so as to normally gravitate toward the surface of the drum and to be freely movable away from the same.

2. In a sand-milling apparatus, the combination of a rotary toothed drum, a pair of depending arms pivotally hung from a point substantially vertically above the axis of said drum, secured to the lower end of said arms and '00- operating with said drum, whereby the abutment plate will-normally gravitate toward the surface of the drum.

3. In a sand-milling apparatus, the combination of a vertical delivery chute, a toothed drum journaled across the upper end of said chute, a concave abutment plate located opposite one side of said drum and pivotally suspendedfrom a point above the drum so as to gravitate toward the latter,

and a concave abutment plate and means for delivering sand in a continuous flow into the upper end of said chute between said drum and abutment plate. I

4. In a sand-milling apparatus, the combination of a rotary toothed drum, and an abutment member located opposite one side of the drum and pivotally suspended from a point above the drum and free at its lower end so as to normally gravitate toward the same and to swing freely outwardly or away therefrom.

EDWARD B. MAN LEY.

Witnesses:

SAMUEL N. POND, JOHN E. MGCANNA. 

